Answer:
True possums are marsupials native to Australia (with some varieties found also in New Guinea and the Indonesian island of Sulawesi). Possums are quite different to American opossums.
Possums, like opossums, are marsupials. This means their young are born very undeveloped, and complete their development in the mother's pouch, firmly attached to a teat.
There are about 70 known species of possums. Possums range in size from being as small as an adult human's finger (e.g. pygmy possums), to just over one metre in length, tail included (e.g. brushtail and ringtail possums). Their fur ranges in colour from grey to brown-grey, with some varieties having a russet colour. The Western Pygmy Possum is a bright cinnamon colour.
Possums have long tails which are used for balancing. Their tails are semi prehensile, and they help the animal grip electric wires and narrow tree branches. The brush-tailed possum has a distinctive, thick tail while the ring-tail possum's tail is thinner, with a distinctive curl.
Possums are arboreal; they are adept climbers with sharp claws, and they also use their front claws to grasp and hold food.